1. Field of the Invention
This invention relates to an apparatus for recording and/or reproducing signals on a magnetic tape contained in a cassette having at least one aperture which is alternatively obstructed or unobstructed to respectively indicate that signals may be recorded on the tape or that the tape already has signals recorded thereon which are not to be erased, and more particularly is directed to an improved mode selecting mechanism of such recording and/or reproducing apparatus for preventing establishment of the recording mode of operation when the operatively positioned cassette has its aperture unobstructed.
2. Description of the Prior Art
Tape cassettes for use in recording and/or reproducing apparatus of the above described type are provided with at least one aperture in the peripheral wall of the cassette housing, and with a frangible tab which normally extends across each such aperture for obstructing the latter. When a tape cassette having its aperture obstructed by the respective frangible tab is operatively positioned in a recording and/or reproducing apparatus, either the recording or the reproducing mode of operation of the apparatus can be established by suitable actuation of its mode selecting mechanism. In the recording mode of operation, any signals previously recorded on the tape contained within the cassette are erased therefrom, and new signals are magnetically recorded on the tape. If it is desired to permanently retain the signals recorded on the tape contained in a cassette, the frangible tab is removed so as to leave the respective aperture unobstructed as an indication of that fact. Cassette-type recording and/or reproducing apparatus has been provided with an inadvertent erasing preventing device which detects an unobstructed aperture in an operatively positioned tape cassette and, in response thereto, prevents the establishment of the recording mode of operation by the mode selecting mechanism. Since the recording mode of operation cannot be established, inadvertent erasing of signals previously recorded on the tape is prevented.
In the existing inadvertent erasing preventing device, establishment of the recording mode of operation of the recording and/or reproducing apparatus is blocked by preventing movement of the record push-button that has to be actuated or depressed for establishing the recording mode of operation. In other words, when the inadvertent erasing preventing device detects an unobstructed aperture in an operatively positioned tape cassette, depressing or actuation of the record push-button of the mode selecting mechanism is prevented. However, when actuation or depression of the record push-button is blocked, as aforesaid, the user of the apparatus may not appreciate the significance of the resistance to movement of the record push-button and may seek to forcibly overcome the same with the result that the apparatus is damaged.